33
ENGLISH
Checking procedure of limiting concentration
Check limiting concentration along following steps and take appropri-
ate measure depending on the situation.
Calculate amount of all the replenished refrigerant (kg) per each refrig-
erant system.
Calculate minimum room capacity
Calculate room capacity by regarding a portion as one room or the
smaller room.
- With partition and with opening
which serve as passage of air to
adjoining room
- Without partition
Limiting concentration is the limit of Freon gas concentration
where immediate measures can be taken without hurting human
body when refrigerant leaks in the air. The limiting concentration
shall be described in the unit of kg/m
3
(Freon gas weight per unit
air volume) for facilitating calculation.
Limiting concentration: 0.44kg/m
3
(R410A)
Amount of additional
replenished refrigerant
Total amount of replenished
refrigerant in refrigerant
facility (kg)
+
=
Note : In case one refrigerant facility is
divided into 2 or more refrigerant
systems and each system is
independent, amount of replenished
refrigerant of each system shall be
adopted.
Amount of replenished
refrigerant per one outside
unit system
Amount of replenished
refrigerant at factory shipment
Amount of additionally
replenished refrigerant
depending on piping
length or piping
diameter at customer
Outdoor unit
Indoor unit
Outdoor unit
Indoor unit
Opening
Partition
In the case of opening
without door , or 0.15
% or more openings
(to floor space) both
above and below door)
Outdoor unit
(No.1 system)
Flow of
refrigerant
Indoor unit
Room where refrigerant leaks
(Refrigerant of the whole No.1
system flows out.)
The installer and system specialist shall secure safety against leakage
according to local regulations or standards.
The following standards may be applicable if local regulations are not
available.
Introduction
Though the R410A refrigerant is harmless and incombustible itself ,
the room to equip the air conditioner should be large to such an extent
that the refrigerant gas will not exceed the limiting concentration even
if the refrigerant gas leaks in the room.
Limiting concentration
- With partition and without opening which serve as passage of air to
adjoining room
Calculate refrigerant concentration
Total amount of replenishedrefrigerant
in refrigerant facility (kg)
Capacity of smallest room
whereindoor unit is installed (m
3
)
- In case the result of calculation exceeds the limiting concentration, perform
the same calculations by shifting to the second smallest, and the third small-
est rooms until at last the result is below the limiting concentration.
= Refrigerant concentration(kg/m
3
)
(R410A)
Outdoor unit
Indoor unit
Smallest
room
In case the concentration exceeds the limit
When the concentration exceeds the limit, change original plan or take
one of the countermeasures shown below:
- Countermeasure 1
Provide opening for ventilation.
Provide 0.15% or more opening to floor space both above and below
door, or provide opening without door.
- Countermeasure 2
Provide gas leak alarm linked with mechanical ventilator.
Countermeasure 2
Gas leak alarm
Mechanical ventilator
Countermeasure 1
Opening effective to ventilation
Indoor unit
Pay special attention to the place, such as a basement, etc. where
refrigerant can be present, since refrigerant is heavier than air.
CAUTION FOR REFRIGERANT LEAK
Summary of Contents for ARUN40GS2A
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